Hana Brožová

Handedness does not predict side of onset of motor symptoms in Parkinson's disease

This study focused on the relationship between the asymmetry of initial motor symptoms of Parkinsons disease (PD) and premorbid handedness of patients. Structural equation modeling has been used for this purpose. The survey consisting of validated items measuring handedness and questions related to side of occurrence of initial symptoms was administered to 472 patients with PD [277 men, 195 women, mean age 66.5 (9.3), mean duration of the disease 10 (6.1) years]. The unidimensional model of handedness fits the data well (χ2 = 37.86, df = 20, P = 0.009, Root Mean Square Error of Approximation = 0.044, Comparative Fit Index = 1.00, Standardized Root Mean Square Residual = 0.042) and side of initial motor symptoms is not significantly related to the factor of handedness (r =0.11, SE = 0.07, P = 0.14). In contrast to several other studies, the results indicate that the side of first occurrence of PD signs cannot be predicted from premorbid handedness of patients.

Grooved Pegboard Predicates More of Cognitive Than Motor Involvement in Parkinson’s Disease

The Grooved Pegboard Test (GPT) was conceived as a test of manual dexterity, upper-limb motor speed, and hand–eye coordination. The aim of our study was to test the componential structure of the GPT on an archetypal model of motor impairment, Parkinson’s disease (PD). A total of 45 PD patients (33 males, 12 females; age M = 67, range = 49-81; PD duration M = 10, range = 6-20 years; H/Y stage 2, range = 2-3) and 20 age- and education-matched controls (14 males, 6 females; age M = 66, range = 48-80) were included. All participants were investigated using the GPT, Short Falls Efficacy Scale–International, Frontal Assessment Battery (FAB), Montreal Cognitive Assessment (MoCA), and Non-Motor Symptom Scale. Patients were followed for 6 months, using fall diaries and monthly phone calls to define PD fallers (falls ≥ 1; n = 27) and PD nonfallers (falls = 0; n = 18). Using structural equation modeling, the GPT predicted performance on the MoCA (p < .001), but not on the FAB (p = .29). In conclusion, analysis of the structure of the GPT provided evidence about important cognitive features, in addition to the motor component of this test in PD.

Predicting Falls in Parkinson Disease: What Is the Value of Instrumented Testing in OFF Medication State?

Background Falls are a common complication of advancing Parkinsons disease (PD). Although numerous risk factors are known, reliable predictors of future falls are still lacking. The objective of this prospective study was to investigate clinical and instrumented tests of balance and gait in both OFF and ON medication states and to verify their utility in the prediction of future falls in PD patients. Methods Forty-five patients with idiopathic PD were examined in defined OFF and ON medication states within one examination day including PD-specific clinical tests, instrumented Timed Up and Go test (iTUG) and computerized dynamic posturography. The same gait and balance tests were performed in 22 control subjects of comparable age and sex. Participants were then followed-up for 6 months using monthly fall diaries and phone calls. Results During the follow-up period, 27/45 PD patients and 4/22 control subjects fell one or more times. Previous falls, fear of falling, more severe motor impairment in the OFF state, higher PD stage, more pronounced depressive symptoms, higher daily levodopa dose and stride time variability in the OFF state were significant risk factors for future falls in PD patients. Increased stride time variability in the OFF state in combination with faster walking cadence appears to be the most significant predictor of future falls, superior to clinical predictors. Conclusion Incorporating instrumented gait measures into the baseline assessment battery as well as accounting for both OFF and ON medication states might improve future fall prediction in PD patients. However, instrumented testing in the OFF state is not routinely performed in clinical practice and has not been used in the development of fall prevention programs in PD. New assessment methods for daylong monitoring of gait, balance and falls are thus required to more effectively address the risk of falling in PD patients.

Eye Movements in Ephedrone-Induced Parkinsonism

Patients with ephedrone parkinsonism (EP) show a complex, rapidly progressive, irreversible, and levodopa non-responsive parkinsonian and dystonic syndrome due to manganese intoxication. Eye movements may help to differentiate parkinsonian syndromes providing insights into which brain networks are affected in the underlying disease, but they have never been systematically studied in EP. Horizontal and vertical eye movements were recorded in 28 EP and compared to 21 Parkinsons disease (PD) patients, and 27 age- and gender-matched healthy subjects using standardized oculomotor tasks with infrared videooculography. EP patients showed slow and hypometric horizontal saccades, an increased occurrence of square wave jerks, long latencies of vertical antisaccades, a high error rate in the horizontal antisaccade task, and made more errors than controls when pro- and antisaccades were mixed. Based on oculomotor performance, a direct differentiation between EP and PD was possible only by the velocity of horizontal saccades. All remaining metrics were similar between both patient groups. EP patients present extensive oculomotor disturbances probably due to manganese-induced damage to the basal ganglia, reflecting their role in oculomotor system.

Changes of hand preference in Parkinson’s disease

This study focused on the difference between pre-morbid and current hand preference of patients with Parkinson’s disease (PD). A survey instrument comprised items measuring pre-morbid and current hand preference and question related to the side of occurrence of initial symptoms. These questions were administered to 471 PD patients. The results show a significant change of pre-morbid right hand preference toward using the left when the side of PD onset was on the right hand and vice versa. Disease duration does not predict the amount of hand preference shift.

New non-linear color look-up table for visualization of brain fractional anisotropy based on normative measurements - principals and first clinical use.

Fractional anisotropy (FA) is the most commonly used quantitative measure of diffusion in the brain. Changes in FA have been reported in many neurological disorders, but the implementation of diffusion tensor imaging (DTI) in daily clinical practice remains challenging. We propose a novel color look-up table (LUT) based on normative data as a tool for screening FA changes. FA was calculated for 76 healthy volunteers using 12 motion-probing gradient directions (MPG), a subset of 59 subjects was additionally scanned using 30 MPG. Population means and 95% prediction intervals for FA in the corpus callosum, frontal gray matter, thalamus and basal ganglia were used to create the LUT. Unique colors were assigned to inflection points with continuous ramps between them. Clinical use was demonstrated on 17 multiple system atrophy (MSA) patients compared to 13 patients with Parkinson disease (PD) and 17 healthy subjects. Four blinded radiologists classified subjects as MSA/non-MSA. Using only the LUT, high sensitivity (80%) and specificity (84%) were achieved in differentiating MSA subjects from PD subjects and controls. The LUTs generated from 12 and 30 MPG were comparable and accentuate FA abnormalities.